The objective is to develop understanding of mechanisms by which pesticides and some of their metabolic products participate directly or indirectly in ion transport through lipid membranes. Two types of phenomena will be studied: (1) the mechanism of modification of ion permeability of lipid membranes by pesticides derived from chlorinated phenoxy and benzoic acids, and (2) the kinetics of charge transport and associated transfer of hydrogen ions across membranes induced in the presence of pesticides derived from chlorinated phenols and nitrophenols. The investigations will be based on measurements of steady-state and transient conductance of membranes, adsorption of pesticides in both neutral and ionized forms on membranes, changes of interfacial electrical potential difference, AC membrane capacitance and conductance, and changes of thermodynamic transitions of lipids in membranes.